Publication Type: | Journal Article |
Year of Publication: | 1972 |
Authors: | Dwernychuk, LW, Boag, DA |
Journal: | The Journal of Wildlife Management |
Volume: | 36 |
Issue: | 3 |
Date Published: | 1972 |
ISBN Number: | 0022541X |
Keywords: | Corvidae, Laridae, Larus, Larus californicus, Larus delawarensis, Pica, Pica hudsonia, Pica pica |
Abstract: | The importance of vegetative cover in protecting duck nests from egg-eating birds was evaluated over two seasons on two islands in a lake in central Alberta, Canada. Avian species recorded preying upon the eggs of ducks included ring-billed gulls (Larus delawarensis), California gulls (L. californicus), crows (Corvus brachyrhynchus), and black-billed magpies (Pica pica). Apparently egg pilfering occurred when nests were unattended, mainly during the laying stage. No relationship could be demonstrated between egg loss and amount of screening cover at actual duck nests, possibly because all other factors at the nests were not equal. At artificially placed nests, egg loss was inversely correlated with the amount of overhead cover, suggesting that visibility of eggs was a major factor in their destruction. However, avian predators must have used additional visual cues in locating well-hidden nests, the most likely being disturbed vegetation. |
URL: | http://www.jstor.org/stable/3799456 |
Short Title: | The Journal of Wildlife Management |
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